By Topic

Generation, Transmission and Distribution, IEE Proceedings C

Issue 6 • Date November 1981

Filter Results

Displaying Results 1 - 14 of 14
  • Wind-energy recovery by a static Scherbius induction generator

    Page(s): 317 - 324
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (879 KB)  

    The paper describes a technique for controlling a doubly fed induction generator driven by a windmill, or other form of variable-speed prime mover, to provide power generation into the national grid system. The secondary circuit of the generator is supplied at a variable frequency from a current source inverter which for test purposes is rated to allow energy recovery, from a simulated windmill, from maximum speed to standstill. To overcome the stability problems normally associated with doubly fed machines a novel signal generator, which is locked in phase with the rotor EMF, controls the secondary power to provide operation over a wide range of subsynchronous and supersynchronous speeds. Consideration of power flow enables the VA rating of the secondary power source to be determined as a function of the gear ratio and online operating range of the system. A simple current source model is used to predict performance which is compared with experimental results. The results indicate a viable system, and suggestions for further work are proposed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Power-system dynamic equivalents:coherency recognition via the rate of change of kinetic energy

    Page(s): 325 - 333
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1030 KB)  

    The coherency aggregation method has proved very successful in the determination of dynamic equivalents of sections of a power system, its main drawback being the extensive computation times required to recognise the coherent groups with full-time simulation. The paper demonstrates the advantages of using the new `rate of change of kinetic energy¿¿ method for coherency recognition in relation to other existing methods. A fault is applied on the power system, an approximate critical clearance time is obtained and machine conditions at that stage are used for recognition. Studies in a large power system are reported. Equivalents are obtained and compared with those produced through full simulation and with the method of the singular points. The effect of fault location on the equivalents obtained is reported. The transient responses of the equivalents produced by the different methods are compared with those of the original system View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Method of calculating the vulnerability of an overhead transmission line to faults caused by galloping

    Page(s): 334 - 341
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (894 KB)  

    An attempt is made to identify the spans or sections of an overhead line route that are most vulnerable to galloping. Methods are presented for calculating from meteorological records the probability of the occurrence of galloping of clashing amplitude. The methods are perfectly general, given the necessary data. Using available data from meteorological stations, the methods are applied to two specific CEGB routes. The results give reasonable agreement on the relative vulnerability to clashing of different line designs, but poor agreement otherwise. Although a large number of remote automatic meteorological stations would be required to improve predictions, it is suggested that a better way to identify troublespots in the same timescale is to install distance-to-fault locators. The paper concludes that substantial numbers of `anti-galloping¿¿ devices would be required if galloping to clashing amplitudes is a random event not restricted to specific `rogue¿¿ spans View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Survey osf TRV conditions on the CEGB 400kV system

    Page(s): 342 - 350
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1114 KB)  

    The paper presents results of a survey of transient recovery voltage (TRV) on the CEGB 400 kV system, made by a series of digital-computer calculations, to provide a basis for the preparation of TRV parameters for a revised switchgear purcinising specification. The results are obtained for 3-phase earthed fault and single-phase-to-earth fault conditions. Details of the system represented in the survey are given, together with the method of representation and analysis of results. The relationship between fault current and rate of rise of TRV is discussed, and factors affecting peak voltage are considered View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Calculation of the transmission capacity of long-distance EHV single-core submarine cable systems

    Page(s): 351 - 359
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (795 KB)  

    A general calculation method for the analysis of transmission capability of a long-distance single-core AC submarine cable system is presented. The method is based on modal transformation of voltages and currents in multiconductor cable systems. Using this method, numerical calculations on 500kV submarine cable systems have been performed with particular reference to the effect of the distance between bonds connecting metallic sheath, outer conductor and armour on the transmission capacity of the system. It was clarified by the analysis that the transmission capcity of the system increased with decreasing bond intervals. Examination of the current distributions between various conductors along the length showed that this increase of transmission capacity was mainly due to the dispersion of the charging current into the metallic sheath, outer conductor and armouring at the bonding points. Finally, analytical results for the transmission capacities of long-distance 500 kV single-core oil-filled submarine cable systems are given by comparing the two cases of single-armoured and double-armoured cables View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Full text access may be available. Click article title to sign in or learn about subscription options.
  • Full text access may be available. Click article title to sign in or learn about subscription options.
  • Editorial. Introduction to special section: Static compensation for AC power systems

    Page(s): 362 - 365
    Save to Project icon | PDF file iconPDF (636 KB)  
    Freely Available from IEEE
  • Shunt-connected reactors and capacitors controlled by thyristors

    Page(s): 366 - 373
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1463 KB)  

    Two basic schemes for thyristor-controlled static compensators are described, namely, thyristorswitched capacitors (TSC) and thyristor-controlled reactors (TCR). A more advanced scheme using a combination of TSC and TCR is presented. It is shown that this combination gives a greater degree of flexibility in the designing of a compensator. The paper also briefly describes the control system in a compensator comprising both thyristor.controlled reactors, thyristor-switched capacitors and reactors (TSR). One method to damp power oscillations, using TSC with a certain control strategy, is presented. The problem of unbalanced loads and load balancing methods using TSC and TCR aie discussed. It is shown that the combined system (TSC/TCR) generates very low harmonics, because the TSC does not generate any harmonics. Finally, some pictures from the first installations comprising both TSC and TCR are shown View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Reactive compensation. Control of shunt compensation with reference to new design concepts

    Page(s): 374 - 381
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1158 KB)  

    The three main aspects; principles, means, and control techniques, of modern shunt compensators are described. Basic circuit arrangements are shown and operating principles are illustrated by waveform diagrams and oscillograms. Economic status and future trends of shunt compensators are discussed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Reactive compensation. Problems and concepts of static compensator control

    Page(s): 382 - 388
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (857 KB)  

    The paper is in three parts. In the first part, general control problems are discussed which arise whenever static compensation is used, irrespective of the applications concept chosen, e.g. variation of the closed-loop response, effects of resonances in the network impedance, maintenance of a certain reserve of power in the SVS (static VAR system) to cover faults. In the second part, a comparison is made between systems with fixed capacitor banks and systems with thyristor-switched capacitors. Here the main point is the differences from the point of view of the control techniques applied. The third part contains a summary of the structure and functional units needed for voltage control, and also the various options for VAR regulation and SVS control of switchable compensators View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Reactive compensation. Role of static compensation meeting AC system control requirements with particular to the James Bay system

    Page(s): 389 - 393
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (575 KB)  

    The paper has three Sections. The first deals with the functions that static compensators must perform to meet the control requirements of an AC system, notably control of the system voltage. The second deals with the types of static compensators that can be applied to these functions and the studies that have been made to demonstrate this application. The third Section examines the performance specification of the compensator and the system requirements. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Reactive compensation. EHVseries capacitor equipment protection and control

    Page(s): 394 - 401
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1242 KB)  

    Since the introduction of static VAR systems (SVS), interest in series compensation has been somewhat reduced. However, in aiming at an economical solution of maximum power transfer on a system, both methods have to be studied together objectively. Basically, to control the series impedance of a power system is, in fact, more effective than control of the shunt impedances. To meet transient stability demands, high-speed controls of the series capacitor have been developed, which have not always given expected service experience, perhaps because of an unnecessary degree of sophistication. The paper describes various schemes designed with the motto `The simpler the better¿¿. Also, the subsynchronous resonance (SSR), at present giving a somewhat negative attitude to series compensation, is discussed in the paper on the basis of computer studies and tests View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Choice of analytical and modelling methods for reactive compensation equipment

    Page(s): 402 - 406
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (685 KB)  

    Modern reactive compensation equipment exhibits nonlinear characteristics which could give rise to unsatisfactory operation. Analytical studies are required in the design stage of such equipment and also in the application phase. The paper examines the modelling techniques available for such studies and considers their application in a range of system conditions. Losses are shown to be important in setting a lower limit to the size of physical models. Mathematical models are discussed in relation to the difficulties in securing a fully comprehensive mathematical model. Finally, the problems of modelling compensation plant for a DC transmission system convertor station are considered briefly, since this is an area of particular interest to many View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.